Tips & Tricks for Iray for newbies......

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  • OstadanOstadan Posts: 1,080

    The page is a full sphere picture of the sky; the bright belt running in a sine curve is the plane of the Milky Way, tilted.  The TIF files does contain dim star data for a lot of stars (it is a deep map), but looks nothing like the greyish sky in the first picture.  And of course it is only a small fraction of the image from that page, since it the image covers the entire sky, and the camera doesn't.  The image on the right is much closer to what I see if I just bring the TIF file into an image editor.

  • SzarkSzark Posts: 10,633

    you can fixed (as in not being gamma correct) inside Daz Studio. Click on the image thumb in the Environment Tab of the render settings and choose Image Editor from the pop up menu. The gamma is most likely set at 0.00 meaning it will estimate the gamma coorrection. Set it to the original image gamma, usally 2.20 and try a render.

  • IceDragonArtIceDragonArt Posts: 12,468

    Cornea, I start with Water shader, then adjust refraction to 1.34, top coat 1.0, white, fresnel, IOR 1.38, roughness 0 (going off of some suggestions of Mec4D).
    Note that if you use any glossy roughness with a transparent object, it looks cloudy/frosted.
    I shut off Eye Reflection (cutout 0.0)
    Iris, I usually use the default optimized skin, which is glossy .2, roughness .24.

    Where is the fresnel and IOR located?

  • Oso3DOso3D Posts: 14,414
    edited January 2016

    Top coat bit, 'top coat Layering Mode: Reflectivity (is the default, switch it to fresnel)'
    Once on Fresnel, the next entry is Top Coat IOR

    (You need Top Coat Weight to be >0 for those to appear)

     

    Post edited by Oso3D on
  • IceDragonArtIceDragonArt Posts: 12,468

    Top coat bit, 'top coat Layering Mode: Reflectivity (is the default, switch it to fresnel)'
    Once on Fresnel, the next entry is Top Coat IOR

    (You need Top Coat Weight to be >0 for those to appear)

     

    Thank you!

     

  • JohannaJohanna Posts: 119
    edited January 2016

    For example, here is a quick 5 minute render.

    It uses Ocean Wide and the Ocean Wide skydome, and a Greek ship model.

    Steps:

    Ocean wide, add Ocean Calm and Midday skydome.

    Convert all materials to Iray Uber Shader

    Change skydome emission to cd/cm2, luminosity 2.

    Hide all lights except Sun-on, make it Photometric, set Luminous Flux to 10

    Change render mode to Interactive

    Change Ocean Calm displacement subd to 3.

     

    And... that's it.

     

    Strange we can have an animated result looking better like this in real time in Second Life. What needs 5 minutes on this?

    I understand high quality (rl look) needs a lot of time, ok, but a 5 minutes rendering for a preview quality is really old school.

    Post edited by Johanna on
  • JohannaJohanna Posts: 119
    edited January 2016

    http://virtualworldsailing.invisionzone.com/uploads/gallery/album_87/gallery_11_87_169678.png

    ... a sample

    ... even the ppl, the water, the clouds and the spray particles are animated (not preloaded) and the boats react to the wind like RL, rendered 25 fps ...

     

    ... 5 minutes for a preview is 1990 like but not 2016 like at all.

    Post edited by Johanna on
  • I don't understand lighting in iray. Iray automatically lights your scene, correct? How do you add lights? I want to add a spot light but I don't see an option to create photmetric lights to add to a scene. So far I can add a distant light and turn it as sun but that is it. How do you a create lights for a simple portrait without having to buy an iray light set?

  • Richard HaseltineRichard Haseltine Posts: 71,487
    edited February 2016

    I don't understand lighting in iray. Iray automatically lights your scene, correct? How do you add lights? I want to add a spot light but I don't see an option to create photmetric lights to add to a scene. So far I can add a distant light and turn it as sun but that is it. How do you a create lights for a simple portrait without having to buy an iray light set?

    The light types were merged - just create a spot light (say) and its properties will change according to the render engine. Iray doesn't quite automatically light the scene, but the default settings use the Ruins HDR map applied to the virtual dome as lighting (see the Environemtn group in Render Settings - which also controls what light sources are considred in rendering).

    Post edited by Richard Haseltine on
  • Okay Thanks

  • IceDragonArtIceDragonArt Posts: 12,468

    Started working my way through this again since I wansn't smart enough to take notes the first time.  Thankfully I remembered that the skin is different in 4.9 and started backwards lol.  Already halfway through page 4 of legal sized pad of notes but it will be much easier to find than trying wade through 37+ pages as well as some other threads with helpful info.  Is there a thread or anything that explains the fstop, shutter speeds etc and what each one does?  Is it the same as for a camera or does it work slightly differently?  If the same I can just google it.

  • mjc1016mjc1016 Posts: 15,001

      Is there a thread or anything that explains the fstop, shutter speeds etc and what each one does?  Is it the same as for a camera or does it work slightly differently?  If the same I can just google it.

    It's close enough to 'real' that basic photographic skills will get you by...

  • Is it the same as for a camera or does it work slightly differently?  If the same I can just google it.

    The only real difference is that in setting up Iray render parameters you don't need to worry about camera shake or blurring from too long an exposure. And you don't need to worry about graininess from using film with too high an ISO value; turn up the dial and It Just Works™.   

  • IceDragonArtIceDragonArt Posts: 12,468

    Great thank you! 

  • IceDragonArtIceDragonArt Posts: 12,468

    And what does the vignetting setting do?

     

  • Not a feature I've ever used before; interesting. Took a bit of digging and backtracking, but I found the online manual page for Iray's Tonemapping parameters.

    Vignetting - Controls the image brightness in the image periphery compared to the image center, resulting in a circular fully exposed area in the center with darker edges. In a real camera, the angle with which the light hits the film impacts the exposure, causing the image to go darker around the edges. When set to 0.0, vignetting is disabled. The higher this value, the stronger the darkening around the edges.

    This effect is based on the cosine of the angle with which the light ray would hit the film plane and is hence affected by the field-of-view of the camera. It will not work at all for orthographic renderings. A value of 3.0 is similar to what a compact camera would generate.

  • I don't see the emitter shader? Where exactly? Thanks.

  • KhoryKhory Posts: 3,848

    Emitter is part of the Iray ubershader. If you go down to emission color and change it from black you will get the rest of the emission options.

  • JeremyDJeremyD Posts: 255

    I love playing with Vignetting - in Daz or in Photoshop. I think it adds a nice focal point  when the corners of your image are darkened. 

    Not my image -- but I think this is a good example of Vignetting in photography:

     

    Sample-11.jpg
    1024 x 681 - 199K
  • hphoenixhphoenix Posts: 1,333
    edited February 2016
    Khory said:

    Emitter is part of the Iray ubershader. If you go down to emission color and change it from black you will get the rest of the emission options.

    The DAZ Iray Uber Shader does include emission, but it isn't the only one.  There are straight emission shaders and others as well.  But many Iray shaders do not implement emission, so they won't show those parameters.

    emission is part of the MDL hierarchy, specifically as edf (emission distribution functions) along with volumetric, brdf, and such.

     

    Post edited by hphoenix on
  • KhoryKhory Posts: 3,848

    Your correct hphoenix, MDL shaders only show the parameters that they deal with and as far as I know none of the MDL shaders included with Studio are emissive. The Emissive shader that is included uses the Iray uber shader and there was something funky going on with it the last time I looked at it.

  • Oso3DOso3D Posts: 14,414

    Tips for good godrays using iray fog...

    Point sources, ideally spotlights, to create the godrays. Very hard-edged gobbos (stencils/windows/etc that are opaque/transparent, rather than a lot of subtle shades)

    Background light and main light oriented mostly 180 degrees from each other. In other words, light coming in a window, then some more diffuse light near the opposite wall.

    Camera oriented either mostly toward or away from the godray lights.

    If camera is oriented toward the godrays, use a very high SSS direction, like .95-.99. This will cut down on the effect of other light sources and focus on the godrays.

    I haven't checked in detail, but the reverse is probably true -- if the light is coming from behind the camera, set the direction to -.95-.99

     

  • IceDragonArtIceDragonArt Posts: 12,468

    Great thank you!  I was hoping it meant the same thing as it did in photo shop, that will be most fun to play with

  • AngelWingsAngelWings Posts: 1,154
    edited February 2016

    A tip for those using indoor scenes. If you want to do an indoor scene, and you have grainy renders, try removing stuff in the scene that is not in the range of the render. And lower the values of white/light surfaces to 240.240.240. The reason why it gets super grainy is because the light gets trapped inside of the room. It's a ray tracing program so If you put a single beem of light in a white 255.255.255 sphere it will bounce around infinatly because it has no place to be absorbed or escape. The inside of the sphere will never clear up 100%. This is why many props have a wall missing, or one side of the prop that is open.... It is not so that your camera can render the scene. It is so that light can escape. Think of it as a ventilation system, for light. The more ventalation your scene light has, the faster it renders, and the cleaner it renders. This is why outdoor scenes look great, and render fast, and indoor  scenes take a long time, and can become grainy. If you ventalate your indoor scenes well they will clear up fast, and look crisp.

    Post edited by AngelWings on
  • ToborTobor Posts: 2,300
    Khory said:

    Your correct hphoenix, MDL shaders only show the parameters that they deal with and as far as I know none of the MDL shaders included with Studio are emissive. The Emissive shader that is included uses the Iray uber shader and there was something funky going on with it the last time I looked at it.

    Not sure I follow this. At least in 4.8 (haven't installed 4.9 yet -- can't until I finish with a project), there is really only one Uber Iray MDL (irayubermaterial.mdl), and it's applied for all of the Uber shaders. I *think* this is the point you're trying to make. Maybe you and hphoenix are talking about the nVidia example MDLs, none of which entail the emissive (emf) function.

    What is the "funky" behavior that is happening? Is this referring to 4.9? irayubermaterial contains a lot of conditional flags that enable and disable functions -- it works this way to minimize the drag on the renderer when a function isn't needed. If they got the programming wrong with these in the 4.9 release, it could affect the way the functions work. Fortunately, it's easy to modify this file.

  • KhoryKhory Posts: 3,848

    There is only one uber iray mdl but there are 41 of the nvida MDL shaders. Those are pretty much pure MDL shaders and if you look at how they are implimented via studio you will see that the call back to the original MDL file vs the uber which heavily modified in studio.

    As for the funky behavior its just a bad shader if your starting out with emissive lights and don't know much about what your doing. For one thing the temp is 2900 which is fine if the end user knows to change it in order to adjust the color but my money would be on most first timers changing that via the emissive color. So changing that to blue would give them green. The default on it is as for is luminance is pretty low for cd/m^d at 5000. It pretty much renders as a dark yellow non emissive unless the user knows to change it to a higher amount. At least with the uber defaults they will will start with what is considered the white for light in Studio. Though admittedly it will be non effective as a light without changes.

  • kyoto kidkyoto kid Posts: 35,504

    A tip for those using indoor scenes. If you want to do an indoor scene, and you have grainy renders, try removing stuff in the scene that is not in the range of the render. And lower the values of white/light surfaces to 240.240.240. The reason why it gets super grainy is because the light gets trapped inside of the room. It's a ray tracing program so If you put a single beem of light in a white 255.255.255 sphere it will bounce around infinatly because it has no place to be absorbed or escape. The inside of the sphere will never clear up 100%. This is why many props have a wall missing, or one side of the prop that is open.... It is not so that your camera can render the scene. It is so that light can escape. Think of it as a ventilation system, for light. The more ventalation your scene light has, the faster it renders, and the cleaner it renders. This is why outdoor scenes look great, and render fast, and indoor  scenes take a long time, and can become grainy. If you ventalate your indoor scenes well they will clear up fast, and look crisp.

    ...interesting concept.

  • hphoenixhphoenix Posts: 1,333

    A tip for those using indoor scenes. If you want to do an indoor scene, and you have grainy renders, try removing stuff in the scene that is not in the range of the render. And lower the values of white/light surfaces to 240.240.240. The reason why it gets super grainy is because the light gets trapped inside of the room. It's a ray tracing program so If you put a single beem of light in a white 255.255.255 sphere it will bounce around infinatly because it has no place to be absorbed or escape. The inside of the sphere will never clear up 100%. This is why many props have a wall missing, or one side of the prop that is open.... It is not so that your camera can render the scene. It is so that light can escape. Think of it as a ventilation system, for light. The more ventalation your scene light has, the faster it renders, and the cleaner it renders. This is why outdoor scenes look great, and render fast, and indoor  scenes take a long time, and can become grainy. If you ventalate your indoor scenes well they will clear up fast, and look crisp.

    This is not at all correct.

    Iray is not a ray-tracing program.  It does incorporate beam-tracing (which has some similarities) but is more a radiosity-based hybrid with beam-tracing.  Also, even in raytracing systems. infinite recursion is never permitted, which is why there is a max ray depth.  Light never gets 'trapped', it bounces a up to a maximum number of object-interections, then simply returns the diffuse contribution up through the recursion.  Also, raytracing engines do not trace the light....only the view to non-light objects.  Lights are only calculated against based on the incident vs normal at the points of object intersection.  The light rays aren't traced from the sources.

    The reason outdoor scenes look 'great' in Iray is that the default settings for an 'outdoor' scene are easier to set up, and work decently with the default camera settings.  It has absolutely nothing to do with 'ventilating' the scene to 'let light escape'.

    Indoor scenes can look just as great, if not better, if you take the time to light them correctly, and set your camera parameters correctly as well.

     

  • ToborTobor Posts: 2,300
    Khory said:

    As for the funky behavior its just a bad shader if your starting out with emissive lights and don't know much about what your doing. For one thing the temp is 2900 which is fine if the end user knows to change it in order to adjust the color but my money would be on most first timers changing that via the emissive color. So changing that to blue would give them green. The default on it is as for is luminance is pretty low for cd/m^d at 5000. It pretty much renders as a dark yellow non emissive unless the user knows to change it to a higher amount. At least with the uber defaults they will will start with what is considered the white for light in Studio. Though admittedly it will be non effective as a light without changes.

    The behavior is pretty much reflects the intended purpose of emissives in Iray, so it's not really "funky." Though they can be used for scene lighting, emissive geometries are more intended as in-scene elements, notably as simulating light bulbs -- not being the light bulbs that illuminate a scene. Iray has far more efficient primitive light types that are coupled with D|S's standard lighting fixtures, making it unnecessary to use mesh lights for lighting rigs in most cases.

    I realize some early adopters of Iray got all excited about mesh lights in Iray because of their experience with other renderers, but they started using them without understanding their limitations, especially the heavy load they can cause during rendering.

    Also don't forget that in Iray's other mode, Interactive, emissives simply will not cast illumination onto the scene. This is an important consideration if you're wanting to do scene passes with canvases (shadow and AO passes only work in Interactive mode), or do faster renders with a simpler engine. 

    Only some of the Uber shaders are useful without tweaking -- the metal ones can mostly be used "out of the box," but most of the others require some adaptation for the scene. So I don't see the need to adjust off the defaults as a negative. This doesn't mean I wouldn't have selected other defaults, though. I might have left color temperature at 0, so then the color would only be affected by Emission Color (this also simplifies the calculations Iray must do, since that part of the math is removed). That would make it easier for newbies. I would also have selected cd/cm^2 as the default, with a far lower value to compensate, as all other light sources in D|S are based on the centimeter unit. 

  • KhoryKhory Posts: 3,848

    Tabor, I guess I am looking at it from the new user perspective. If they load that shader and render with no changes they get what is basically a dark yellow that casts no light. For them it is not just a funky outcome but pretty worthless and off putting. I'm not talking about potential since most new users expect a shader preset to just "work". At least with the Uber defaults they won't get a muddy yellow that they have to start out with. And solving "why isn't it  bright enough" is less complex than solving "why is it so ugly". Having or choosing to adjust presets is not a negative if your in tune with what they are expected to do and how they do it. But if your a new user that isn't always clear or easy and it really is a better deal for them if they "work out of the box". When they give a result that seems counter to the expected outcome that can be really off putting for a newer user.

    I understand how emissive lights work but I'm not actually a newbie to Iray. In fact I just finished a light set that uses both the photometric and the emissive lights in order to get the look that I wanted. And I have been working on emissive shaders and lighted props on and off for over a month. I tend to use kcd/m^2 for the same reason you use cd/cm^2, because you can use lower luminance settings which I think are easier to fine tune.

     

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